Recent Met Office and European model runs indicate overnight minima in London around 17–19°C for August 5, with trader consensus split between 18°C and 19°C reflecting modest spread in ensemble guidance. Building high pressure favors partly clear skies and light winds that promote limited radiative cooling, while higher humidity and residual cloud from prior Atlantic flow cap how far temperatures drop. Urban heat-island effects at London City Airport further moderate the lowest reading relative to rural sites. Model disagreement on exact cloud timing and wind strength over the next 48 hours keeps the 16–20°C range tightly bunched, with resolution hinging on the final observed minimum at the official station.